Soft tissue repair · Other

21501

Incision and drainage of a deep abscess or hematoma in the soft tissues of the neck or thorax

Verified May 8, 2026 · 6 sources ↓

Medicare
$517.71
Total RVUs
15.5
Global, days
90
Region
Other
Drawn from CMSAAPCMdclarityAAOS

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 6 cited references ↓

  • Specify depth of infection or hematoma — explicitly document that the abscess or hematoma involves deep soft tissue, not subcutaneous layer alone
  • Anatomic location within the neck or thorax, including laterality if applicable (e.g., left posterior neck, right anterior chest wall)
  • Description of intraoperative findings: estimated volume of fluid drained, character of contents (purulent, sanguineous, serosanguineous), presence of loculations
  • Operative note must name the surgical approach and depth of dissection required to access the abscess cavity
  • Pre-operative diagnosis with supporting ICD-10 code (e.g., deep neck space abscess, post-traumatic hematoma) — must align with procedure indication
  • Any cultures sent intraoperatively should be documented, along with drain placement if applicable

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 21501 covers surgical incision and drainage of a deep-space abscess or hematoma located in the soft tissues of the neck or thorax. The key word is 'deep' — this code applies when the infection or hematoma has penetrated below the superficial subcutaneous layer into deeper soft tissue planes. Superficial neck or chest wall abscesses drained in the office or ED typically fall under skin and subcutaneous I&D codes, not 21501.

The 90-day global period means all routine follow-up visits, wound checks, and dressing changes through day 90 are bundled. If the same surgeon performs a staged or related return procedure within that window, append modifier 58. An unplanned return to the OR for a related complication — repacking, re-drainage — takes modifier 78. A separate, unrelated procedure in the global window takes modifier 79.

Laterality modifiers LT and RT are applicable when the site is clearly unilateral. When same-day E/M is billed alongside this procedure, modifier 25 is required on the E/M to survive NCCI edits. If a second surgeon performed the same drainage on the same day due to repeat necessity, append modifier 77.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU3.88
Practice expense RVU10.79
Malpractice RVU0.83
Total RVU15.5
Medicare national rate$517.71
Global period90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

SettingMedicare rate (national)
Office (PFS non-facility)
Procedure performed in physician's office
$517.71
HOPD (APC 5073)
Hospital outpatient department
$2,967.63
ASC (PI A2)
Ambulatory surgical center (freestanding)
$1,248.36

Common denial reasons

The recurring reasons claims for CPT 21501 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

  • Depth not documented — payer downcodes to a superficial I&D code when operative note doesn't explicitly confirm deep tissue involvement
  • Laterality missing when LT or RT modifier expected by payer for unilateral soft-tissue procedures
  • Global period conflict — unbundled follow-up visit billed without modifier 24 (unrelated E/M) or 78 (related return to OR) during the 90-day window
  • Diagnosis mismatch — ICD-10 code reflects a superficial or skin-level abscess rather than a deep soft-tissue or deep neck space infection
  • Missing modifier 25 on a same-day E/M, causing automatic bundling with the surgical procedure under NCCI edits

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01How do I distinguish 21501 from a superficial neck or chest I&D code?
21501 requires the abscess or hematoma to be in the deep soft tissues — below the superficial subcutaneous layer. If the drainage is of a skin or subcutaneous abscess on the neck or chest wall, you're looking at codes in the 10060–10180 range instead. The operative note must confirm deep tissue dissection to support 21501.
02The patient returned to the OR 3 weeks post-op for re-drainage of a recurrent abscess at the same site. Which modifier applies?
Modifier 78 — unplanned return to the OR for a related procedure during the global period. The original 90-day global is still running, so the re-drainage is related. Do not use modifier 79, which is reserved for unrelated procedures. Document the unplanned nature and the relationship to the original procedure.
03Can I bill a same-day E/M with 21501?
Yes, but modifier 25 is required on the E/M code. The E/M must be separately documented and medically necessary beyond the pre-procedure assessment. Without modifier 25, NCCI edits will bundle it into the surgical fee.
04Is 21501 appropriate for a post-operative hematoma drained in the office?
Only if it requires formal deep surgical dissection. A simple needle aspiration or superficial evacuation of a post-op hematoma at the neck or chest doesn't support 21501. If you return to the OR and open the wound to evacuate a deep hematoma, 21501 with modifier 78 is appropriate during the global period.
05Does 21501 carry a 90-day global, and what does that include?
Yes, 21501 has a 90-day global period per CMS Physician Fee Schedule 2026. That bundles the day-before visit, the surgery, and all routine post-op care through day 90. Wound checks, dressing changes, and drain removal are all included. Separately bill only for unrelated E/M (modifier 24), staged procedures (modifier 58), or complications requiring return to the OR (modifier 78).
06Should I use LT or RT modifiers on 21501?
Yes, when the procedure is clearly unilateral. Append LT or RT to specify the operative side. Some payers require laterality modifiers for soft-tissue procedures and will flag claims without them for manual review. If bilateral drainage is performed, modifier 50 applies, though bilateral deep neck or thoracic I&D in a single session is uncommon.

Mira AI Scribe

Mira's AI scribe captures the depth of dissection, anatomic location, laterality, and character of drained contents directly from surgeon dictation. It flags when the operative note uses vague language like 'soft tissue abscess' without specifying deep versus superficial involvement — the single most common documentation gap that triggers a payer downcode or denial on 21501.

See how Mira captures CPT 21501 documentation

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